The megamaser galaxy III ZW 35.

III Zw 35 is a pair of galaxies characterized by intense OH maser emission, and powerful far-infrared and radio continuum. We have made a detailed study of the galaxy pair based on optical, infrared and radio observations. The brighter northern component is identified as a LINER or Seyfert galaxy and contains an active nuclear region from which radio continuum, OH maser and thermal dust emission are detected. We propose that the northern component has a compact active nucleus deeply embedded in an obscured region of diameter about 210 pc within which enhanced star-formation occurs. The lower luminosity, southern component is of low mass and is undergoing starburst activity over an extended region of diameter about 5.5 kpc. The origin of the starburst and nonthermal activity appears to be an interaction between the two components.